UG288: Si72xx-WD-Kit User s Guide The Si72xx-WD-Kit allows for the evaluation of the Si72xx Hall Sensors through eight demos on the EFM32 Happy Gecko STK. Each of the six base part types are included KEY POINTS in the kit on small, postage-stamp-sized (PS) boards with an evaluation demo for each. This user guide describes a quick-start procedure to start the evaluation easily as well 8 demos as a full description of each demo and a list of compatible PS boards. Wheel demo showing wheel angular position The Si72xx-WD Rev 2 Kit includes the following: Wheel demo showing revolution counting (1) Si72XX-EXP Rev2 Board Si7210 postage-stamp-sized board demos (1) Si7201-B01V-EB Switch PS Board including magnetic field data on two (1) Si7202-B01V-EB Latch PS Board scales and temperature Switch, analog, PWM, and SENT postage- (1) Si7210-B00V-EB I2C PS Board stamp-sized board demos including (1) Si7211-B00V-EB Analog PS Board tamper indication with an Si7210 (1) Si7212-B00V-EB PWM PS Board (1) Si7213-B00V-EB SENT PS Board (1) 6-pin, 8-inch ribbon cable (2) Loose magnets for PS demos (1) CR2032 Coin Cell battery (1) Micro USB cable silabs.com Building a more connected world. Rev. 0.2 UG288: Si72xx-WD-Kit User s Guide Demos 1. Demos 1.1 Demo 1Wheel Angular Position (Si72xx-EXP) Section 9 ofAN1018: Using the Si72xx Hall-Effect Magnetic Position Sensor covers how the hall sensor can be used for a positional measurement by moving the magnetic field. Furthermore, it explains how an MCU can perform an angular position measurement by arranging two hall sensors to sense magnetic field variations from two magnets arranged about the shaft underneath. Figure 1.1. Wheel Angular Position Demo The Wheel Angle Calculation demo determines the angular position of the wheel using two magnetic sensors mounted 90 apart on top of the EXP. Underneath the sensors, a wheel board is connected by a nylon screw which houses two magnets positioned at 45 and 225. The figures below show the magnets orientated 180 apart, in opposite polarity on the wheel board and how the wheel aligns with the EXP positioning. Using the wheel board as an angle reference, the sensors are positioned so that when U2 is at 0, U1 is positioned at 270. Figure 1.2. SI72xx-EXP Wheel Alignment Figure 1.3. Wheel Magnet Orientation silabs.com Building a more connected world. Rev. 0.2 2